The present invention relates to pay television systems generally and more particularly to systems for controlling access to pay television transmissions.
Many pay television systems today employ xe2x80x9csmart cardsxe2x80x9d which are cards of the size of credit cards that include integrated circuits (IC). Typically, the smart cards are used to enable access to television transmissions. In such a case, a subscriber inserts a smart card in a slot in a cable television decoder to allow access to television transmissions.
Usually, one smart card is associated with one television (TV) set and the subscriber receives one smart card upon payment of a subscription fee. The subscriber may also purchase, at a reduced price, additional smart cards for use with other TV sets in his house.
In such a case, there is a possibility that the subscriber may try to purchase many cards, and sell most of them to other people at a price which is lower than the regular price, but higher than the price that the subscriber has paid for them. This may cause substantial losses to operators of television transmission systems.
In a co-pending U.S. patent application to Doron Handelman et al., Ser. No. 08/375,995 filed on Jan. 20, 1995, entitled xe2x80x9cSecure Access Systemsxe2x80x9d, and assigned to the same assignee as the present application, as well as in corresponding European application 95115554.8 filed on Oct. 2, 1995, there is described a parental control system which utilizes two smart cards that are inserted in a decoder. When one of the cards, which is a main card, is inserted in the decoder, access is enabled to non-restricted programs only. When both cards are inserted in the decoder, access is enabled to restricted programs as well as to non-restricted programs.
The present invention seeks to provide systems and methods for controlling access to pay television transmissions at a site in which a plurality of pay television decoders are placed.
There is thus provided in accordance with a preferred embodiment of the present invention a pay television system including:
a pay television network;
a subscriber unit which receives pay television transmissions via the pay television network and displays the pay television transmissions on televisions coupled thereto, the subscriber unit including at least two pay television decoders, wherein a first decoder includes a first card reader and a second decoder includes a second card reader;
a first smart card which is operative, upon insertion in a first slot in the first card reader, to activate decoding of the pay television transmissions in the first decoder; and
a second smart card which is operative, upon insertion in a second slot in the second card reader, to activate decoding of the pay television transmissions in the second decoder, wherein
the second smart card is operable to deactivate in accordance with predetermined criteria, and to reactivate upon insertion in the first slot in the first card reader after removal of the first smart card from the first card reader.
Preferably, the predetermined criteria include at least one of a predetermined time and a predetermined date.
In accordance with a preferred embodiment of the present invention the predetermined criteria include a predetermined date, and the first smart card is operable to deactivate at a first deactivation date, the second smart card is operable to deactivate at a second deactivation date, and the first deactivation date is later than the second deactivation date.
Preferably, at least one of the first smart card and the second smart card is also operable to control access to a video-cassette-recorder for recording pay television transmissions.
Further in accordance with a preferred embodiment of the present invention the second smart card receives, upon reactivation, a new deactivation date which is later than the second deactivation date. The new deactivation date is provided by one of the first decoder, the first smart card and a pay television headend.
Preferably, the new deactivation date is provided by adding a time increment to a current system time, and calculation of the new deactivation date is performed at one of the first decoder, the first smart card, and the headend.
In accordance with a preferred embodiment of the present invention reactivation of the second smart card includes transmission of chaining data, the chaining data including one of a signature, a key and a seed which is operable to at least one of validate, identify, verify and authenticate the second smart card. The chaining data also includes a digital representation of a time increment which is associated with a current system time to provide a deactivation date.
In a preferred embodiment of the invention the one of a signature, a key and a seed is identical for the first smart card and for the second smart card.
Further in accordance with a preferred embodiment of the present invention the predetermined criteria include a predetermined date, and the second smart card is operable to deactivate at any time of day during the predetermined date.
In a preferred embodiment of the present invention the first smart card and the second smart card are interchangeable.
There is also provided in accordance with a preferred embodiment of the present invention a pay television decoder including:
a smart card reader including a smart card slot via which a first smart card is read;
a decoder memory, coupled to the smart card reader, which is operable to store one of a signature, a key and a seed identifying the first smart card; and
a decoder processor, coupled to the decoder memory, which is operable to calculate a deactivation date based on data received from one of the first smart card, a pay television headend and the decoder memory, wherein
the decoder processor is operable to provide the deactivation date to a second smart card, when the second smart card is inserted in the smart card slot and read via the smart card reader, in response to a match between the one of a signature, a key and a seed identifying the first smart card and a corresponding one of a signature, a key and a seed identifying the second smart card.
In accordance with another preferred embodiment of the present invention there is provided a pay television decoder including:
a smart card reader including a smart card slot via which a first smart card is read; and
a decoder memory, coupled to the smart card reader, which is operable:
to store a deactivation date of a second smart card, and one of a signature, a key and a seed identifying the first smart card,
to provide the one of a signature, a key and a seed identifying the first smart card to the second smart card, when the second smart card is inserted in the smart card slot in the smart card reader, in response to a first instruction transmitted by the second smart card, and
to provide the deactivation date to the second smart card in response to a second instruction transmitted by the second smart card.
Preferably, the second instruction is transmitted in response to a match between the one of a signature, a key and a seed identifying the first smart card, and a corresponding one of a signature, a key and a seed identifying the second smart card.
There is also provided in accordance with a preferred embodiment of the present invention a pay television access control method to be employed in a pay television system in which pay television programs are transmitted to a plurality of subscribers, each being entitled to receive selected programs, the method including:
providing a first decoder activated by a first smart card to decode pay television transmissions, and a second decoder activated by a second smart card to decode pay television transmissions;
deactivating the second smart card in accordance with predetermined criteria;
removing the first smart card from a first card reader in the first decoder; and
reactivating the second smart card by inserting the second smart card in the first card reader of the first decoder.
Preferably, the predetermined criteria include at least one of a predetermined time and a predetermined date.
Further in accordance with a preferred embodiment of the present invention the predetermined criteria include a predetermined date, and the method includes deactivating the first smart card at a first deactivation date, and deactivating the second smart card at a second deactivation date, wherein the first deactivation date is later than the second deactivation date.
Preferably, the method also includes supplying a new deactivation date to the second smart card upon reactivation. The supplying step includes adding a time increment to a current system time.
There is also provided in accordance with a preferred embodiment of the present invention a pay television access control method including:
providing, in a pay television decoder, a smart card reader including a smart card slot via which a first smart card is read, and a decoder memory, coupled to the smart card reader, which is operable to store one of a signature, a key and a seed identifying the first smart card;
coupling, to the decoder memory, a decoder processor which is operable to calculate a deactivation date based on data received from one of the first smart card, a pay television headend and the decoder memory;
inserting in the smart card slot in the smart card reader a second smart card; and
providing the deactivation date to the second smart card in response to a match between the one of a signature, a key and a seed identifying the first smart card and a corresponding one of a signature, a key and a seed identifying the second smart card.
In accordance with another preferred embodiment of the present invention there is provided a pay television access control method including:
providing, in a pay television decoder, a smart card reader including a smart card slot via which a first smart card is read, and a decoder memory coupled to the smart card reader;
storing, in the decoder memory, a deactivation date of a second smart card, and one of a signature, a key and a seed identifying the first smart card;
inserting the second smart card in the smart card slot in the smart card reader;
supplying the one of a signature, a key and a seed identifying the first smart card to the second smart card in response to a first instruction transmitted by the second smart card; and
transmitting the deactivation date to the second smart card in response to a second instruction generated by the second smart card.
Further in accordance with another preferred embodiment of the present invention there is provided a pay television access control method including:
providing a decoder including a decoder memory and a smart card reader;
inserting a first smart card in the smart card reader;
transferring, from the first smart card to the decoder memory, chaining data for activating a second smart card;
removing the first smart card from the smart card reader;
inserting the second smart card in the smart card reader;
transmitting, from the decoder memory to the second smart card, the chaining data; and
enabling the chaining data to activate the second smart card.